SemaStmt.cpp revision 64789f8496d9bd3ff5ba3686feca0de1a25d5a32
1//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements semantic analysis for statements. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/AST/ASTContext.h" 16#include "clang/AST/DeclObjC.h" 17#include "clang/AST/Expr.h" 18#include "clang/AST/Stmt.h" 19#include "clang/Parse/Scope.h" 20#include "clang/Basic/TargetInfo.h" 21#include "clang/Basic/Diagnostic.h" 22#include "clang/Basic/LangOptions.h" 23#include "llvm/ADT/SmallString.h" 24using namespace clang; 25 26Sema::StmtResult Sema::ActOnExprStmt(ExprTy *expr) { 27 Expr *E = static_cast<Expr*>(expr); 28 assert(E && "ActOnExprStmt(): missing expression"); 29 30 // C99 6.8.3p2: The expression in an expression statement is evaluated as a 31 // void expression for its side effects. Conversion to void allows any 32 // operand, even incomplete types. 33 34 // Same thing in for stmt first clause (when expr) and third clause. 35 return E; 36} 37 38 39Sema::StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc) { 40 return new NullStmt(SemiLoc); 41} 42 43Sema::StmtResult Sema::ActOnDeclStmt(DeclTy *decl, SourceLocation StartLoc, 44 SourceLocation EndLoc) { 45 if (decl == 0) 46 return true; 47 48 ScopedDecl *SD = cast<ScopedDecl>(static_cast<Decl *>(decl)); 49 return new DeclStmt(SD, StartLoc, EndLoc); 50} 51 52Action::StmtResult 53Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, 54 StmtTy **elts, unsigned NumElts, bool isStmtExpr) { 55 Stmt **Elts = reinterpret_cast<Stmt**>(elts); 56 // If we're in C89 mode, check that we don't have any decls after stmts. If 57 // so, emit an extension diagnostic. 58 if (!getLangOptions().C99 && !getLangOptions().CPlusPlus) { 59 // Note that __extension__ can be around a decl. 60 unsigned i = 0; 61 // Skip over all declarations. 62 for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) 63 /*empty*/; 64 65 // We found the end of the list or a statement. Scan for another declstmt. 66 for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) 67 /*empty*/; 68 69 if (i != NumElts) { 70 ScopedDecl *D = cast<DeclStmt>(Elts[i])->getDecl(); 71 Diag(D->getLocation(), diag::ext_mixed_decls_code); 72 } 73 } 74 // Warn about unused expressions in statements. 75 for (unsigned i = 0; i != NumElts; ++i) { 76 Expr *E = dyn_cast<Expr>(Elts[i]); 77 if (!E) continue; 78 79 // Warn about expressions with unused results. 80 if (E->hasLocalSideEffect() || E->getType()->isVoidType()) 81 continue; 82 83 // The last expr in a stmt expr really is used. 84 if (isStmtExpr && i == NumElts-1) 85 continue; 86 87 /// DiagnoseDeadExpr - This expression is side-effect free and evaluated in 88 /// a context where the result is unused. Emit a diagnostic to warn about 89 /// this. 90 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) 91 Diag(BO->getOperatorLoc(), diag::warn_unused_expr, 92 BO->getLHS()->getSourceRange(), BO->getRHS()->getSourceRange()); 93 else if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 94 Diag(UO->getOperatorLoc(), diag::warn_unused_expr, 95 UO->getSubExpr()->getSourceRange()); 96 else 97 Diag(E->getExprLoc(), diag::warn_unused_expr, E->getSourceRange()); 98 } 99 100 return new CompoundStmt(Elts, NumElts, L, R); 101} 102 103Action::StmtResult 104Sema::ActOnCaseStmt(SourceLocation CaseLoc, ExprTy *lhsval, 105 SourceLocation DotDotDotLoc, ExprTy *rhsval, 106 SourceLocation ColonLoc, StmtTy *subStmt) { 107 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 108 Expr *LHSVal = ((Expr *)lhsval), *RHSVal = ((Expr *)rhsval); 109 assert((LHSVal != 0) && "missing expression in case statement"); 110 111 SourceLocation ExpLoc; 112 // C99 6.8.4.2p3: The expression shall be an integer constant. 113 if (!LHSVal->isIntegerConstantExpr(Context, &ExpLoc)) { 114 Diag(ExpLoc, diag::err_case_label_not_integer_constant_expr, 115 LHSVal->getSourceRange()); 116 return SubStmt; 117 } 118 119 // GCC extension: The expression shall be an integer constant. 120 if (RHSVal && !RHSVal->isIntegerConstantExpr(Context, &ExpLoc)) { 121 Diag(ExpLoc, diag::err_case_label_not_integer_constant_expr, 122 RHSVal->getSourceRange()); 123 RHSVal = 0; // Recover by just forgetting about it. 124 } 125 126 if (SwitchStack.empty()) { 127 Diag(CaseLoc, diag::err_case_not_in_switch); 128 return SubStmt; 129 } 130 131 CaseStmt *CS = new CaseStmt(LHSVal, RHSVal, SubStmt, CaseLoc); 132 SwitchStack.back()->addSwitchCase(CS); 133 return CS; 134} 135 136Action::StmtResult 137Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, 138 StmtTy *subStmt, Scope *CurScope) { 139 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 140 141 if (SwitchStack.empty()) { 142 Diag(DefaultLoc, diag::err_default_not_in_switch); 143 return SubStmt; 144 } 145 146 DefaultStmt *DS = new DefaultStmt(DefaultLoc, SubStmt); 147 SwitchStack.back()->addSwitchCase(DS); 148 149 return DS; 150} 151 152Action::StmtResult 153Sema::ActOnLabelStmt(SourceLocation IdentLoc, IdentifierInfo *II, 154 SourceLocation ColonLoc, StmtTy *subStmt) { 155 Stmt *SubStmt = static_cast<Stmt*>(subStmt); 156 // Look up the record for this label identifier. 157 LabelStmt *&LabelDecl = LabelMap[II]; 158 159 // If not forward referenced or defined already, just create a new LabelStmt. 160 if (LabelDecl == 0) 161 return LabelDecl = new LabelStmt(IdentLoc, II, SubStmt); 162 163 assert(LabelDecl->getID() == II && "Label mismatch!"); 164 165 // Otherwise, this label was either forward reference or multiply defined. If 166 // multiply defined, reject it now. 167 if (LabelDecl->getSubStmt()) { 168 Diag(IdentLoc, diag::err_redefinition_of_label, LabelDecl->getName()); 169 Diag(LabelDecl->getIdentLoc(), diag::err_previous_definition); 170 return SubStmt; 171 } 172 173 // Otherwise, this label was forward declared, and we just found its real 174 // definition. Fill in the forward definition and return it. 175 LabelDecl->setIdentLoc(IdentLoc); 176 LabelDecl->setSubStmt(SubStmt); 177 return LabelDecl; 178} 179 180Action::StmtResult 181Sema::ActOnIfStmt(SourceLocation IfLoc, ExprTy *CondVal, 182 StmtTy *ThenVal, SourceLocation ElseLoc, 183 StmtTy *ElseVal) { 184 Expr *condExpr = (Expr *)CondVal; 185 Stmt *thenStmt = (Stmt *)ThenVal; 186 187 assert(condExpr && "ActOnIfStmt(): missing expression"); 188 189 DefaultFunctionArrayConversion(condExpr); 190 QualType condType = condExpr->getType(); 191 192 if (!condType->isScalarType()) // C99 6.8.4.1p1 193 return Diag(IfLoc, diag::err_typecheck_statement_requires_scalar, 194 condType.getAsString(), condExpr->getSourceRange()); 195 196 // Warn if the if block has a null body without an else value. 197 // this helps prevent bugs due to typos, such as 198 // if (condition); 199 // do_stuff(); 200 if (!ElseVal) { 201 if (NullStmt* stmt = dyn_cast<NullStmt>(thenStmt)) 202 Diag(stmt->getSemiLoc(), diag::warn_empty_if_body); 203 } 204 205 return new IfStmt(IfLoc, condExpr, thenStmt, (Stmt*)ElseVal); 206} 207 208Action::StmtResult 209Sema::ActOnStartOfSwitchStmt(ExprTy *cond) { 210 Expr *Cond = static_cast<Expr*>(cond); 211 212 // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. 213 UsualUnaryConversions(Cond); 214 215 SwitchStmt *SS = new SwitchStmt(Cond); 216 SwitchStack.push_back(SS); 217 return SS; 218} 219 220/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have 221/// the specified width and sign. If an overflow occurs, detect it and emit 222/// the specified diagnostic. 223void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, 224 unsigned NewWidth, bool NewSign, 225 SourceLocation Loc, 226 unsigned DiagID) { 227 // Perform a conversion to the promoted condition type if needed. 228 if (NewWidth > Val.getBitWidth()) { 229 // If this is an extension, just do it. 230 llvm::APSInt OldVal(Val); 231 Val.extend(NewWidth); 232 233 // If the input was signed and negative and the output is unsigned, 234 // warn. 235 if (!NewSign && OldVal.isSigned() && OldVal.isNegative()) 236 Diag(Loc, DiagID, OldVal.toString(), Val.toString()); 237 238 Val.setIsSigned(NewSign); 239 } else if (NewWidth < Val.getBitWidth()) { 240 // If this is a truncation, check for overflow. 241 llvm::APSInt ConvVal(Val); 242 ConvVal.trunc(NewWidth); 243 ConvVal.setIsSigned(NewSign); 244 ConvVal.extend(Val.getBitWidth()); 245 ConvVal.setIsSigned(Val.isSigned()); 246 if (ConvVal != Val) 247 Diag(Loc, DiagID, Val.toString(), ConvVal.toString()); 248 249 // Regardless of whether a diagnostic was emitted, really do the 250 // truncation. 251 Val.trunc(NewWidth); 252 Val.setIsSigned(NewSign); 253 } else if (NewSign != Val.isSigned()) { 254 // Convert the sign to match the sign of the condition. This can cause 255 // overflow as well: unsigned(INTMIN) 256 llvm::APSInt OldVal(Val); 257 Val.setIsSigned(NewSign); 258 259 if (Val.isNegative()) // Sign bit changes meaning. 260 Diag(Loc, DiagID, OldVal.toString(), Val.toString()); 261 } 262} 263 264namespace { 265 struct CaseCompareFunctor { 266 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 267 const llvm::APSInt &RHS) { 268 return LHS.first < RHS; 269 } 270 bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, 271 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 272 return LHS.first < RHS.first; 273 } 274 bool operator()(const llvm::APSInt &LHS, 275 const std::pair<llvm::APSInt, CaseStmt*> &RHS) { 276 return LHS < RHS.first; 277 } 278 }; 279} 280 281/// CmpCaseVals - Comparison predicate for sorting case values. 282/// 283static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, 284 const std::pair<llvm::APSInt, CaseStmt*>& rhs) { 285 if (lhs.first < rhs.first) 286 return true; 287 288 if (lhs.first == rhs.first && 289 lhs.second->getCaseLoc().getRawEncoding() 290 < rhs.second->getCaseLoc().getRawEncoding()) 291 return true; 292 return false; 293} 294 295Action::StmtResult 296Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, StmtTy *Switch, 297 ExprTy *Body) { 298 Stmt *BodyStmt = (Stmt*)Body; 299 300 SwitchStmt *SS = SwitchStack.back(); 301 assert(SS == (SwitchStmt*)Switch && "switch stack missing push/pop!"); 302 303 SS->setBody(BodyStmt, SwitchLoc); 304 SwitchStack.pop_back(); 305 306 Expr *CondExpr = SS->getCond(); 307 QualType CondType = CondExpr->getType(); 308 309 if (!CondType->isIntegerType()) { // C99 6.8.4.2p1 310 Diag(SwitchLoc, diag::err_typecheck_statement_requires_integer, 311 CondType.getAsString(), CondExpr->getSourceRange()); 312 return true; 313 } 314 315 // Get the bitwidth of the switched-on value before promotions. We must 316 // convert the integer case values to this width before comparison. 317 unsigned CondWidth = static_cast<unsigned>(Context.getTypeSize(CondType)); 318 bool CondIsSigned = CondType->isSignedIntegerType(); 319 320 // Accumulate all of the case values in a vector so that we can sort them 321 // and detect duplicates. This vector contains the APInt for the case after 322 // it has been converted to the condition type. 323 typedef llvm::SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; 324 CaseValsTy CaseVals; 325 326 // Keep track of any GNU case ranges we see. The APSInt is the low value. 327 std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRanges; 328 329 DefaultStmt *TheDefaultStmt = 0; 330 331 bool CaseListIsErroneous = false; 332 333 for (SwitchCase *SC = SS->getSwitchCaseList(); SC; 334 SC = SC->getNextSwitchCase()) { 335 336 if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { 337 if (TheDefaultStmt) { 338 Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); 339 Diag(TheDefaultStmt->getDefaultLoc(), diag::err_first_label); 340 341 // FIXME: Remove the default statement from the switch block so that 342 // we'll return a valid AST. This requires recursing down the 343 // AST and finding it, not something we are set up to do right now. For 344 // now, just lop the entire switch stmt out of the AST. 345 CaseListIsErroneous = true; 346 } 347 TheDefaultStmt = DS; 348 349 } else { 350 CaseStmt *CS = cast<CaseStmt>(SC); 351 352 // We already verified that the expression has a i-c-e value (C99 353 // 6.8.4.2p3) - get that value now. 354 llvm::APSInt LoVal(32); 355 Expr *Lo = CS->getLHS(); 356 Lo->isIntegerConstantExpr(LoVal, Context); 357 358 // Convert the value to the same width/sign as the condition. 359 ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, 360 CS->getLHS()->getLocStart(), 361 diag::warn_case_value_overflow); 362 363 // If the LHS is not the same type as the condition, insert an implicit 364 // cast. 365 ImpCastExprToType(Lo, CondType); 366 CS->setLHS(Lo); 367 368 // If this is a case range, remember it in CaseRanges, otherwise CaseVals. 369 if (CS->getRHS()) 370 CaseRanges.push_back(std::make_pair(LoVal, CS)); 371 else 372 CaseVals.push_back(std::make_pair(LoVal, CS)); 373 } 374 } 375 376 // Sort all the scalar case values so we can easily detect duplicates. 377 std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); 378 379 if (!CaseVals.empty()) { 380 for (unsigned i = 0, e = CaseVals.size()-1; i != e; ++i) { 381 if (CaseVals[i].first == CaseVals[i+1].first) { 382 // If we have a duplicate, report it. 383 Diag(CaseVals[i+1].second->getLHS()->getLocStart(), 384 diag::err_duplicate_case, CaseVals[i].first.toString()); 385 Diag(CaseVals[i].second->getLHS()->getLocStart(), 386 diag::err_duplicate_case_prev); 387 // FIXME: We really want to remove the bogus case stmt from the substmt, 388 // but we have no way to do this right now. 389 CaseListIsErroneous = true; 390 } 391 } 392 } 393 394 // Detect duplicate case ranges, which usually don't exist at all in the first 395 // place. 396 if (!CaseRanges.empty()) { 397 // Sort all the case ranges by their low value so we can easily detect 398 // overlaps between ranges. 399 std::stable_sort(CaseRanges.begin(), CaseRanges.end()); 400 401 // Scan the ranges, computing the high values and removing empty ranges. 402 std::vector<llvm::APSInt> HiVals; 403 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 404 CaseStmt *CR = CaseRanges[i].second; 405 llvm::APSInt HiVal(32); 406 Expr *Hi = CR->getRHS(); 407 Hi->isIntegerConstantExpr(HiVal, Context); 408 409 // Convert the value to the same width/sign as the condition. 410 ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, 411 CR->getRHS()->getLocStart(), 412 diag::warn_case_value_overflow); 413 414 // If the LHS is not the same type as the condition, insert an implicit 415 // cast. 416 ImpCastExprToType(Hi, CondType); 417 CR->setRHS(Hi); 418 419 // If the low value is bigger than the high value, the case is empty. 420 if (CaseRanges[i].first > HiVal) { 421 Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range, 422 SourceRange(CR->getLHS()->getLocStart(), 423 CR->getRHS()->getLocEnd())); 424 CaseRanges.erase(CaseRanges.begin()+i); 425 --i, --e; 426 continue; 427 } 428 HiVals.push_back(HiVal); 429 } 430 431 // Rescan the ranges, looking for overlap with singleton values and other 432 // ranges. Since the range list is sorted, we only need to compare case 433 // ranges with their neighbors. 434 for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { 435 llvm::APSInt &CRLo = CaseRanges[i].first; 436 llvm::APSInt &CRHi = HiVals[i]; 437 CaseStmt *CR = CaseRanges[i].second; 438 439 // Check to see whether the case range overlaps with any singleton cases. 440 CaseStmt *OverlapStmt = 0; 441 llvm::APSInt OverlapVal(32); 442 443 // Find the smallest value >= the lower bound. If I is in the case range, 444 // then we have overlap. 445 CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), 446 CaseVals.end(), CRLo, 447 CaseCompareFunctor()); 448 if (I != CaseVals.end() && I->first < CRHi) { 449 OverlapVal = I->first; // Found overlap with scalar. 450 OverlapStmt = I->second; 451 } 452 453 // Find the smallest value bigger than the upper bound. 454 I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); 455 if (I != CaseVals.begin() && (I-1)->first >= CRLo) { 456 OverlapVal = (I-1)->first; // Found overlap with scalar. 457 OverlapStmt = (I-1)->second; 458 } 459 460 // Check to see if this case stmt overlaps with the subsequent case range. 461 if (i && CRLo <= HiVals[i-1]) { 462 OverlapVal = HiVals[i-1]; // Found overlap with range. 463 OverlapStmt = CaseRanges[i-1].second; 464 } 465 466 if (OverlapStmt) { 467 // If we have a duplicate, report it. 468 Diag(CR->getLHS()->getLocStart(), 469 diag::err_duplicate_case, OverlapVal.toString()); 470 Diag(OverlapStmt->getLHS()->getLocStart(), 471 diag::err_duplicate_case_prev); 472 // FIXME: We really want to remove the bogus case stmt from the substmt, 473 // but we have no way to do this right now. 474 CaseListIsErroneous = true; 475 } 476 } 477 } 478 479 // FIXME: If the case list was broken is some way, we don't have a good system 480 // to patch it up. Instead, just return the whole substmt as broken. 481 if (CaseListIsErroneous) 482 return true; 483 484 return SS; 485} 486 487Action::StmtResult 488Sema::ActOnWhileStmt(SourceLocation WhileLoc, ExprTy *Cond, StmtTy *Body) { 489 Expr *condExpr = (Expr *)Cond; 490 assert(condExpr && "ActOnWhileStmt(): missing expression"); 491 492 DefaultFunctionArrayConversion(condExpr); 493 QualType condType = condExpr->getType(); 494 495 if (!condType->isScalarType()) // C99 6.8.5p2 496 return Diag(WhileLoc, diag::err_typecheck_statement_requires_scalar, 497 condType.getAsString(), condExpr->getSourceRange()); 498 499 return new WhileStmt(condExpr, (Stmt*)Body, WhileLoc); 500} 501 502Action::StmtResult 503Sema::ActOnDoStmt(SourceLocation DoLoc, StmtTy *Body, 504 SourceLocation WhileLoc, ExprTy *Cond) { 505 Expr *condExpr = (Expr *)Cond; 506 assert(condExpr && "ActOnDoStmt(): missing expression"); 507 508 DefaultFunctionArrayConversion(condExpr); 509 QualType condType = condExpr->getType(); 510 511 if (!condType->isScalarType()) // C99 6.8.5p2 512 return Diag(DoLoc, diag::err_typecheck_statement_requires_scalar, 513 condType.getAsString(), condExpr->getSourceRange()); 514 515 return new DoStmt((Stmt*)Body, condExpr, DoLoc); 516} 517 518Action::StmtResult 519Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, 520 StmtTy *first, ExprTy *second, ExprTy *third, 521 SourceLocation RParenLoc, StmtTy *body) { 522 Stmt *First = static_cast<Stmt*>(first); 523 Expr *Second = static_cast<Expr*>(second); 524 Expr *Third = static_cast<Expr*>(third); 525 Stmt *Body = static_cast<Stmt*>(body); 526 527 if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { 528 // C99 6.8.5p3: The declaration part of a 'for' statement shall only declare 529 // identifiers for objects having storage class 'auto' or 'register'. 530 for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); 531 DI!=DE; ++DI) { 532 VarDecl *VD = dyn_cast<VarDecl>(*DI); 533 if (VD && VD->isBlockVarDecl() && !VD->hasLocalStorage()) 534 VD = 0; 535 if (VD == 0) 536 Diag((*DI)->getLocation(), diag::err_non_variable_decl_in_for); 537 // FIXME: mark decl erroneous! 538 } 539 } 540 if (Second) { 541 DefaultFunctionArrayConversion(Second); 542 QualType SecondType = Second->getType(); 543 544 if (!SecondType->isScalarType()) // C99 6.8.5p2 545 return Diag(ForLoc, diag::err_typecheck_statement_requires_scalar, 546 SecondType.getAsString(), Second->getSourceRange()); 547 } 548 return new ForStmt(First, Second, Third, Body, ForLoc); 549} 550 551Action::StmtResult 552Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, 553 SourceLocation LParenLoc, 554 StmtTy *first, ExprTy *second, 555 SourceLocation RParenLoc, StmtTy *body) { 556 Stmt *First = static_cast<Stmt*>(first); 557 Expr *Second = static_cast<Expr*>(second); 558 Stmt *Body = static_cast<Stmt*>(body); 559 if (First) { 560 QualType FirstType; 561 if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { 562 FirstType = cast<ValueDecl>(DS->getDecl())->getType(); 563 // C99 6.8.5p3: The declaration part of a 'for' statement shall only declare 564 // identifiers for objects having storage class 'auto' or 'register'. 565 ScopedDecl *D = DS->getDecl(); 566 VarDecl *VD = cast<VarDecl>(D); 567 if (VD->isBlockVarDecl() && !VD->hasLocalStorage()) 568 return Diag(VD->getLocation(), diag::err_non_variable_decl_in_for); 569 if (D->getNextDeclarator()) 570 return Diag(D->getLocation(), diag::err_toomany_element_decls); 571 } else 572 FirstType = static_cast<Expr*>(first)->getType(); 573 if (!Context.isObjCObjectPointerType(FirstType)) 574 Diag(ForLoc, diag::err_selector_element_type, 575 FirstType.getAsString(), First->getSourceRange()); 576 } 577 if (Second) { 578 DefaultFunctionArrayConversion(Second); 579 QualType SecondType = Second->getType(); 580 if (!Context.isObjCObjectPointerType(SecondType)) 581 Diag(ForLoc, diag::err_collection_expr_type, 582 SecondType.getAsString(), Second->getSourceRange()); 583 } 584 return new ObjCForCollectionStmt(First, Second, Body, ForLoc, RParenLoc); 585} 586 587Action::StmtResult 588Sema::ActOnGotoStmt(SourceLocation GotoLoc, SourceLocation LabelLoc, 589 IdentifierInfo *LabelII) { 590 // Look up the record for this label identifier. 591 LabelStmt *&LabelDecl = LabelMap[LabelII]; 592 593 // If we haven't seen this label yet, create a forward reference. 594 if (LabelDecl == 0) 595 LabelDecl = new LabelStmt(LabelLoc, LabelII, 0); 596 597 return new GotoStmt(LabelDecl, GotoLoc, LabelLoc); 598} 599 600Action::StmtResult 601Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc,SourceLocation StarLoc, 602 ExprTy *DestExp) { 603 // FIXME: Verify that the operand is convertible to void*. 604 605 return new IndirectGotoStmt((Expr*)DestExp); 606} 607 608Action::StmtResult 609Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { 610 Scope *S = CurScope->getContinueParent(); 611 if (!S) { 612 // C99 6.8.6.2p1: A break shall appear only in or as a loop body. 613 Diag(ContinueLoc, diag::err_continue_not_in_loop); 614 return true; 615 } 616 617 return new ContinueStmt(ContinueLoc); 618} 619 620Action::StmtResult 621Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { 622 Scope *S = CurScope->getBreakParent(); 623 if (!S) { 624 // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. 625 Diag(BreakLoc, diag::err_break_not_in_loop_or_switch); 626 return true; 627 } 628 629 return new BreakStmt(BreakLoc); 630} 631 632 633Action::StmtResult 634Sema::ActOnReturnStmt(SourceLocation ReturnLoc, ExprTy *rex) { 635 Expr *RetValExp = static_cast<Expr *>(rex); 636 QualType FnRetType = 637 getCurFunctionDecl() ? getCurFunctionDecl()->getResultType() : 638 getCurMethodDecl()->getResultType(); 639 640 if (FnRetType->isVoidType()) { 641 if (RetValExp) // C99 6.8.6.4p1 (ext_ since GCC warns) 642 Diag(ReturnLoc, diag::ext_return_has_expr, 643 ( getCurFunctionDecl() ? 644 getCurFunctionDecl()->getIdentifier()->getName() : 645 getCurMethodDecl()->getSelector().getName() ), 646 RetValExp->getSourceRange()); 647 return new ReturnStmt(ReturnLoc, RetValExp); 648 } else { 649 if (!RetValExp) { 650 const char *funcName = 651 getCurFunctionDecl() ? 652 getCurFunctionDecl()->getIdentifier()->getName() : 653 getCurMethodDecl()->getSelector().getName().c_str(); 654 if (getLangOptions().C99) // C99 6.8.6.4p1 (ext_ since GCC warns) 655 Diag(ReturnLoc, diag::ext_return_missing_expr, funcName); 656 else // C90 6.6.6.4p4 657 Diag(ReturnLoc, diag::warn_return_missing_expr, funcName); 658 return new ReturnStmt(ReturnLoc, (Expr*)0); 659 } 660 } 661 // we have a non-void function with an expression, continue checking 662 QualType RetValType = RetValExp->getType(); 663 664 // C99 6.8.6.4p3(136): The return statement is not an assignment. The 665 // overlap restriction of subclause 6.5.16.1 does not apply to the case of 666 // function return. 667 AssignConvertType ConvTy = CheckSingleAssignmentConstraints(FnRetType, 668 RetValExp); 669 if (DiagnoseAssignmentResult(ConvTy, ReturnLoc, FnRetType, 670 RetValType, RetValExp, "returning")) 671 return true; 672 673 if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); 674 675 return new ReturnStmt(ReturnLoc, (Expr*)RetValExp); 676} 677 678Sema::StmtResult Sema::ActOnAsmStmt(SourceLocation AsmLoc, 679 bool IsSimple, 680 bool IsVolatile, 681 unsigned NumOutputs, 682 unsigned NumInputs, 683 std::string *Names, 684 ExprTy **Constraints, 685 ExprTy **Exprs, 686 ExprTy *asmString, 687 unsigned NumClobbers, 688 ExprTy **Clobbers, 689 SourceLocation RParenLoc) { 690 // The parser verifies that there is a string literal here. 691 StringLiteral *AsmString = cast<StringLiteral>((Expr *)asmString); 692 if (AsmString->isWide()) 693 // FIXME: We currently leak memory here. 694 return Diag(AsmString->getLocStart(), diag::err_asm_wide_character, 695 AsmString->getSourceRange()); 696 697 698 for (unsigned i = 0; i < NumOutputs; i++) { 699 StringLiteral *Literal = cast<StringLiteral>((Expr *)Constraints[i]); 700 if (Literal->isWide()) 701 // FIXME: We currently leak memory here. 702 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 703 Literal->getSourceRange()); 704 705 std::string OutputConstraint(Literal->getStrData(), 706 Literal->getByteLength()); 707 708 TargetInfo::ConstraintInfo info; 709 if (!Context.Target.validateOutputConstraint(OutputConstraint.c_str(),info)) 710 // FIXME: We currently leak memory here. 711 return Diag(Literal->getLocStart(), 712 diag::err_invalid_output_constraint_in_asm); 713 714 // Check that the output exprs are valid lvalues. 715 Expr *OutputExpr = (Expr *)Exprs[i]; 716 Expr::isLvalueResult Result = OutputExpr->isLvalue(Context); 717 if (Result != Expr::LV_Valid) { 718 ParenExpr *PE = cast<ParenExpr>(OutputExpr); 719 720 // FIXME: We currently leak memory here. 721 return Diag(PE->getSubExpr()->getLocStart(), 722 diag::err_invalid_lvalue_in_asm_output, 723 PE->getSubExpr()->getSourceRange()); 724 } 725 } 726 727 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { 728 StringLiteral *Literal = cast<StringLiteral>((Expr *)Constraints[i]); 729 if (Literal->isWide()) 730 // FIXME: We currently leak memory here. 731 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 732 Literal->getSourceRange()); 733 734 std::string InputConstraint(Literal->getStrData(), 735 Literal->getByteLength()); 736 737 TargetInfo::ConstraintInfo info; 738 if (!Context.Target.validateInputConstraint(InputConstraint.c_str(), 739 NumOutputs, 740 info)) { 741 // FIXME: We currently leak memory here. 742 return Diag(Literal->getLocStart(), 743 diag::err_invalid_input_constraint_in_asm); 744 } 745 746 // Check that the input exprs aren't of type void. 747 Expr *InputExpr = (Expr *)Exprs[i]; 748 if (InputExpr->getType()->isVoidType()) { 749 ParenExpr *PE = cast<ParenExpr>(InputExpr); 750 751 // FIXME: We currently leak memory here. 752 return Diag(PE->getSubExpr()->getLocStart(), 753 diag::err_invalid_type_in_asm_input, 754 PE->getType().getAsString(), 755 PE->getSubExpr()->getSourceRange()); 756 } 757 } 758 759 // Check that the clobbers are valid. 760 for (unsigned i = 0; i < NumClobbers; i++) { 761 StringLiteral *Literal = cast<StringLiteral>((Expr *)Clobbers[i]); 762 if (Literal->isWide()) 763 // FIXME: We currently leak memory here. 764 return Diag(Literal->getLocStart(), diag::err_asm_wide_character, 765 Literal->getSourceRange()); 766 767 llvm::SmallString<16> Clobber(Literal->getStrData(), 768 Literal->getStrData() + 769 Literal->getByteLength()); 770 771 if (!Context.Target.isValidGCCRegisterName(Clobber.c_str())) 772 // FIXME: We currently leak memory here. 773 return Diag(Literal->getLocStart(), 774 diag::err_unknown_register_name_in_asm, Clobber.c_str()); 775 } 776 777 return new AsmStmt(AsmLoc, 778 IsSimple, 779 IsVolatile, 780 NumOutputs, 781 NumInputs, 782 Names, 783 reinterpret_cast<StringLiteral**>(Constraints), 784 reinterpret_cast<Expr**>(Exprs), 785 AsmString, NumClobbers, 786 reinterpret_cast<StringLiteral**>(Clobbers), 787 RParenLoc); 788} 789 790Action::StmtResult 791Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, 792 SourceLocation RParen, StmtTy *Parm, 793 StmtTy *Body, StmtTy *CatchList) { 794 ObjCAtCatchStmt *CS = new ObjCAtCatchStmt(AtLoc, RParen, 795 static_cast<Stmt*>(Parm), static_cast<Stmt*>(Body), 796 static_cast<Stmt*>(CatchList)); 797 return CatchList ? CatchList : CS; 798} 799 800Action::StmtResult 801Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, StmtTy *Body) { 802 ObjCAtFinallyStmt *FS = new ObjCAtFinallyStmt(AtLoc, 803 static_cast<Stmt*>(Body)); 804 return FS; 805} 806 807Action::StmtResult 808Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, 809 StmtTy *Try, StmtTy *Catch, StmtTy *Finally) { 810 ObjCAtTryStmt *TS = new ObjCAtTryStmt(AtLoc, static_cast<Stmt*>(Try), 811 static_cast<Stmt*>(Catch), 812 static_cast<Stmt*>(Finally)); 813 return TS; 814} 815 816Action::StmtResult 817Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, StmtTy *Throw) { 818 ObjCAtThrowStmt *TS = new ObjCAtThrowStmt(AtLoc, static_cast<Stmt*>(Throw)); 819 return TS; 820} 821 822Action::StmtResult 823Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, ExprTy *SynchExpr, 824 StmtTy *SynchBody) { 825 ObjCAtSynchronizedStmt *SS = new ObjCAtSynchronizedStmt(AtLoc, 826 static_cast<Stmt*>(SynchExpr), static_cast<Stmt*>(SynchBody)); 827 return SS; 828} 829